The data from two deep seismic sounding profiles was processed and studied comprehensively. The results show that crust_mantle structures in the investigated region obviously display layered characteristics and veloci...The data from two deep seismic sounding profiles was processed and studied comprehensively. The results show that crust_mantle structures in the investigated region obviously display layered characteristics and velocity structures and tectonic features have larger distinction in different geological structure blocks. The boundary interface C between the upper and lower crust and Moho fluctuate greatly. The shallowest depths of C (30 0km) and Moho (45 5km) under Jiashi deepen sharply from Jiashi to the western Kunlun mountain areas, where the depths of C and Moho are 44 0km and 70 0km, respectively. The higher velocity structures in the Tarim massif determine its relatively “stable” characteristics in crust tectonics. The phenomenon in the Jiashi region, where the distribution of earthquake foci mostly range from 20km to 40km in depth, may infer that the local uplift of C and Moho interface, anomalously lower velocity bodies and deep large faults control earthquake occurrence and seismogenic processes in the Jiashi strong earthquake swarm.展开更多
Map building by multi-robot is very important to accomplish autonomous navigation,and one of the basic problems and research hotspots is how to merge the maps into a single one in the field of multi-robot map building...Map building by multi-robot is very important to accomplish autonomous navigation,and one of the basic problems and research hotspots is how to merge the maps into a single one in the field of multi-robot map building.A novel approach is put forward based on adaptive differential evolution to map building for the multi-robot system.The multi-robot mapping-building system adopts the methods of decentralized exploration and concentrated mapping.The adaptive differential evolution algorithm is used to search in the space of possible transformation,and the iterative search is performed with the goal of maximizing overlapping regions.The map is translated and rotated so that the two maps can be overlapped and merged into a single global one successfully.This approach for map building can be realized without any knowledge of their relative positions.Experimental results show that the approach is effective and feasibile.展开更多
The MS6.4 Menyuan earthquake occurred on the northern side of the Lenglongling fault(LLLF) in the mid-western of the Qilian-Haiyuan fault zone on January 21, 2016. The earthquake epicenter was distant from the Minle-D...The MS6.4 Menyuan earthquake occurred on the northern side of the Lenglongling fault(LLLF) in the mid-western of the Qilian-Haiyuan fault zone on January 21, 2016. The earthquake epicenter was distant from the Minle-Damaying and Huangcheng-Shuangta faults, eastern of the Northern Qilian Shan fault zone. A near northwest-striking rupture plane intersects the two faults at a certain angle. The focal mechanism solution shows that this was a thrust-type earthquake, slightly different from the strike-slip movement with a thrust component of the LLLF. Field geological mapping, tectonic geomorphology analysis, trench excavation and 14 C dating reveal that(1) the LLLF has been obviously active since the Holocene, and may behave with characteristic slip behavior and produce M_W7.3–7.5 earthquakes;(2) the LLLF appears as a flower structure in terms of structure style, and dips NNE at a steep angle; and(3) the most recent earthquake event occurred after 1815–1065 a BP. An associated fault, the Northern Lenglongling fault(NLLLF), is located at the northwestern end of the LLLF. Consequently, the NLLLF was continually subject to tectonic pushing effects from the left-lateral shear at the end of the LLLF, and, accordingly, it bent and rotated outward tectonically.Subsequently, the fault deviated from the dominant rupture azimuth and activity weakened. In the late Quaternary, it behaved as a thrust fault with no obvious deformation at the surface. This is indicated by the arc shape, with a micro-protrusion northeastward,and no geologic or geomorphic signs of surface rupturing since the late Quaternary. However, such faults could still rupture at depth, producing moderate-strong earthquakes. The geometric and kinematic properties of the NLLLF are in good agreement with the occurrence and kinematic properties of nodal plane 2, and with the distribution characteristics of the aftershocks and seismic intensity. Therefore, the NLLLF is a more suitable seismogenic structure for the MS 6.4 Menyuan earthquake. In addition, the thrust movement of the NLLLF accommodates subsequent movement of the LLLF. During the historical evolution of the NLLLF,the LLLF and the NLLLF have affected the local topography through tectonic uplift.展开更多
文摘The data from two deep seismic sounding profiles was processed and studied comprehensively. The results show that crust_mantle structures in the investigated region obviously display layered characteristics and velocity structures and tectonic features have larger distinction in different geological structure blocks. The boundary interface C between the upper and lower crust and Moho fluctuate greatly. The shallowest depths of C (30 0km) and Moho (45 5km) under Jiashi deepen sharply from Jiashi to the western Kunlun mountain areas, where the depths of C and Moho are 44 0km and 70 0km, respectively. The higher velocity structures in the Tarim massif determine its relatively “stable” characteristics in crust tectonics. The phenomenon in the Jiashi region, where the distribution of earthquake foci mostly range from 20km to 40km in depth, may infer that the local uplift of C and Moho interface, anomalously lower velocity bodies and deep large faults control earthquake occurrence and seismogenic processes in the Jiashi strong earthquake swarm.
基金Supported by the National Natural Science Foundation of China(No.90820302,60805027)the Provincial Natural Science Foundation of Hunan(No.12JJ3064)+1 种基金the Construct Program of the Key Discipline in Hunan Province(No.201176)the Planned Science and Technology Project of Hunan Province(No.2011SK3135,2012FJ3059)
文摘Map building by multi-robot is very important to accomplish autonomous navigation,and one of the basic problems and research hotspots is how to merge the maps into a single one in the field of multi-robot map building.A novel approach is put forward based on adaptive differential evolution to map building for the multi-robot system.The multi-robot mapping-building system adopts the methods of decentralized exploration and concentrated mapping.The adaptive differential evolution algorithm is used to search in the space of possible transformation,and the iterative search is performed with the goal of maximizing overlapping regions.The map is translated and rotated so that the two maps can be overlapped and merged into a single global one successfully.This approach for map building can be realized without any knowledge of their relative positions.Experimental results show that the approach is effective and feasibile.
基金supported by a Special Project on Earthquake Research, the China Active Fault Survey Project-The South-North Seismic Zone Northern Segment (Grant No. 201408023)Fundamental Research Funds in Institute of Crustal Dynamics, China Earthquake Administration (Grant No. ZDJ2015-16)
文摘The MS6.4 Menyuan earthquake occurred on the northern side of the Lenglongling fault(LLLF) in the mid-western of the Qilian-Haiyuan fault zone on January 21, 2016. The earthquake epicenter was distant from the Minle-Damaying and Huangcheng-Shuangta faults, eastern of the Northern Qilian Shan fault zone. A near northwest-striking rupture plane intersects the two faults at a certain angle. The focal mechanism solution shows that this was a thrust-type earthquake, slightly different from the strike-slip movement with a thrust component of the LLLF. Field geological mapping, tectonic geomorphology analysis, trench excavation and 14 C dating reveal that(1) the LLLF has been obviously active since the Holocene, and may behave with characteristic slip behavior and produce M_W7.3–7.5 earthquakes;(2) the LLLF appears as a flower structure in terms of structure style, and dips NNE at a steep angle; and(3) the most recent earthquake event occurred after 1815–1065 a BP. An associated fault, the Northern Lenglongling fault(NLLLF), is located at the northwestern end of the LLLF. Consequently, the NLLLF was continually subject to tectonic pushing effects from the left-lateral shear at the end of the LLLF, and, accordingly, it bent and rotated outward tectonically.Subsequently, the fault deviated from the dominant rupture azimuth and activity weakened. In the late Quaternary, it behaved as a thrust fault with no obvious deformation at the surface. This is indicated by the arc shape, with a micro-protrusion northeastward,and no geologic or geomorphic signs of surface rupturing since the late Quaternary. However, such faults could still rupture at depth, producing moderate-strong earthquakes. The geometric and kinematic properties of the NLLLF are in good agreement with the occurrence and kinematic properties of nodal plane 2, and with the distribution characteristics of the aftershocks and seismic intensity. Therefore, the NLLLF is a more suitable seismogenic structure for the MS 6.4 Menyuan earthquake. In addition, the thrust movement of the NLLLF accommodates subsequent movement of the LLLF. During the historical evolution of the NLLLF,the LLLF and the NLLLF have affected the local topography through tectonic uplift.
